First Vanguard (ファーストヴァンガード or
Before drawing the opening hand, each fighter chooses any one grade 0 card from their main deck and places it on their vanguard circle face down. This card is known as the player's "first vanguard." If using a ride deck, players instead take the grade 0 unit from their ride deck to use as their first vanguard.
Although it is removed at the start of the game, the first vanguard counts toward the deck's requirement of 50 cards, so if you use card sleeves, the sleeve you use for your first vanguard must match the rest of your main deck. This does not apply if using a ride deck.
According to the official restrictions, a card may be restricted from being used as a first vanguard. This is often done because the card has an extremely useful ability that was deemed unfair to allow a player to have access to it from the start of the game. A card being restricted from being a first vanguard does not affect the number of that card that may be included in a deck; it is simply not allowed to be chosen as the player's first vanguard at the start of the game.